Removal of Methyl Orange from Water Using Sulfur-Modified nZVI Supported on Biochar Composite
A biochar-supported FeS/nZVI hybrid material (S-nZVI/BC) was synthesized and used for methyl orange (MO) removal from aqueous solutions. The effects of the S/Fe ratio, initial pH, MO concentrations, contact time, and coexisting ions were investigated. S-nZVI/BC was characterized by X-ray diffraction, transmission electron microscopy, vibrating sample magnetometer, BET surface areas, and X-ray photoelectron spectroscopy. A 1.44-fold increase in MO removal rate (from 36.84 to 53.13%) was observed as the S/Fe molar ratio increased from 0 to 0.5. The removal of MO was highly pH-dependent and the adsorption kinetics data were in agreement with the pseudo-second-order model. The maximum removal rate of MO (0.5 mM) was 76.09% (1.902 ± 0.229 mmol/g) for S-nZVI/BC at pH 2.5. The presence of Cl−, Ca2+, NH4+, and humic acid exerted an inhibitory effect on MO removal, both at low and high concentrations. These results indicate that the sulfidation process would improve the wastewater treatment efficiency. Another benefit is that S-nZVI/BC could be removed from the solution easily by an external magnetic field.
KeywordsSulfidation nZVI Biochar Dye Degradation
We sincerely thank Mr. Tongning Shang for inspiration during the writing process.
This work was supported by the Natural Science Foundation of Jiangsu Province (CN) (BK20150693), College Students Innovation Project for the R&D of Novel Drugs (no. J1310032), and Fundamental Research Funds for the Central Universities (grant no. 2632018FY01).
- Guan, X., Sun, Y., Qin, H., Li, J., Lo, I., Di, H., et al. (2015). The limitations of applying zero-valent iron technology in contaminants sequestration and the corresponding countermeasures. The development in zero-valent iron technology in the last two decades (1994–2014). Water Research, 75, 224–248.CrossRefGoogle Scholar
- Lin, G., Zhu, N., Wang, L., Bing, X., & Chen, X. (2011). Combined humic acid adsorption and enhanced Fenton processes for the treatment of naphthalene dye intermediate wastewater. Journal of Hazardous Materials, 198(2), 232–240.Google Scholar
- Sun, X., Kurokawa, T., Suzuki, M., Takagi, M., & Kawase, Y. (2015). Removal of cationic dye methylene blue by zero-valent iron. Effects of pH and dissolved oxygen on removal mechanisms. Journal of Environmental Science and Health. Part A, Toxic/Hazardous Substances & Environmental Engineering, 50, 1057–1071.CrossRefGoogle Scholar
- Wang, Y., López-Valdivieso, A., Zhang, T., Mwamulima, T., Zhang, X., Song, S., et al. (2017). Preparation of microscale zero-valent iron-fly ash-bentonite composite and evaluation of its adsorption performance of crystal violet and methylene blue dyes. Environmental Science and Pollution Research, 24, 20050–20062.CrossRefGoogle Scholar
- Yan, W., Lien, H. L., Koel, B. E., & Zhang, W. X. (2013). Iron nanoparticles for environmental clean-up: recent developments and future outlook. Environmental Science: Processes & Impacts, 15(1), 63–77.Google Scholar